Originally posted by Ecxentrique:
actually these buttons are quite standard.. not only for canon.. most advanced camera models will have
extracted from canon eos 1000/ rebel manual:-
Program AE (auto-exposure) mode (P).
Turn the command dial to P. The camera will automatically select shutter and aperture settings according to its built-in basic program. Program AE mode uses continuous wind and also evaluative metering unless you push the partial metering button.
Unlike the green mode you can program shift by turning the main dial and adjust the exposure compensation by turning shift-main dial. (see below)
If the cameraÂ’s maximum shutter speed (1/1000 sec for the Rebel/EOS 1000/1000 QD and 1/2000 sec for the Rebel II/S II/EOS 1000N/1000FN/1000S-QD/1000S-QDP) and the value of the minimum aperture of the lens flash in the viewfinder then thereÂ’s too much light. Either use slower film or put a neutral-density filter in front of the lens. If a shutter speed of 30 seconds and the value of the maximum aperture of the lens flash in the viewfinder then there isnÂ’t enough. Use faster film, flash or bulb mode.
Shutter priority AE mode (Tv).
In this AE mode you set the shutter speed (time) and the camera automatically sets an appropriate lens aperture for you, based on the selected metering mode - evaluative (default) or partial.
Turn the command dial to Tv, which stands for “Time value”. (Nikon more sensibly refer to shutter priority as S mode.) Turn the main dial to adjust the shutter speed setting and shift-main dial to adjust exposure compensation. The camera flashes the aperture value if you’re out of range. (ie: if you haven’t got enough light it’ll flash the maximum aperture of the lens, and if you’ve got too much it’ll flash the minimum aperture of the lens.)
You canÂ’t go into bulb mode here - the maximum time value is 30 seconds. For bulb you need manual mode. The shutter values are expressed as fractions of a second unless the " symbol appears, in which case the value is expressed as a second. Thus 125 means the shutter speed is 1/125 of a second whereas 1"5 means the shutter speed is 1.5 seconds.
Aperture priority AE mode (Av).
In this AE mode you set the lens aperture and the camera automatically sets an appropriate shutter speed for you, based on the selected metering mode - evaluative (default) or partial.
Turn the command dial to Av (for Aperture value). Turn the main dial to adjust the aperture setting and shift-main dial to adjust exposure compensation. The camera flashes the shutter speed value if youÂ’re out of range. (ie: if you havenÂ’t got enough light itÂ’ll flash 30" and if youÂ’ve got too much light itÂ’ll flash 1000 or 2000, whichever is the maximum shutter speed for your particular model)
You can choose any aperture value that falls within the aperture range of the lens you happen to have installed. The wide-open aperture varies a lot from lens to lens - f/1.4, 1.8 and 2.8 are typical values for fast lens and 3.5, 4.5 and 5.6 are typical for slower zoom or telephoto lenses. The largest aperture value is usually printed on the lens itself, and is sometimes an aperture range on zoom lenses which do not have constant apertures - eg: f/3.5-5.6. The smallest aperture value on a 35mm lens is usually f/22.
Metered Manual mode (M).
In this mode you set both the lens aperture and the shutter speed manually. The camera will assist you by telling you whether it thinks you have the correct metering based on the selected metering mode - centre-weighted averaging (default) or partial.
Turning the command dial to M lets you shoot in metered manual. How the camera behaves in this mode depends on which camera you have.
The older 1000/Rebel viewfinders display a simulated needle match mode. This sort of animated graphic tells you if your picture is likely to be underexposed, overexposed or exposed correctly. (correct exposure is obviously when the moving rectangle appears in the middle of the scale)
However, the Rebel II/S II cameras the camera will display little + and - arrows telling you whether your picture is correctly exposed, overexposed or underexposed. Minus means that the image is underexposed and that the camera needs more light; plus means that the image is overexposed and the camera means less light. Both plus and minus means that the camera thinks the exposure is correct. This is not as useful, since the arrows donÂ’t tell you how far youÂ’re under or over. This step backwards in functionality between the version numbers was apparently done for patent licensing reasons.
Either way, use the main dial to change the shutter speed and shift-main dial to change the aperture. You can also go into bulb (long time exposure) mode - it’s the “buLb” setting that’s one step past 30 seconds. However, since the camera lacks any provision for remote shutter release it isn’t a very useful feature unless you rig up a homemade mechanical lever to keep the button pressed during long exposures. Bulb mode means the shutter stays open for as long as you keep the shutter release button pressed. Apparently the name comes from the olden days of mechanical shutter releases, when you’d have a rubber ball-shaped bulb that you’d squeeze to trigger and hold the shutter.
I understand the camera switches to centre-weighted averaging metering mode when you go into manual mode, which is annoying, since you canÂ’t specify evaluative if you happen to prefer that. You can always go into partial by pressing and holding the awkward partial metering button.
thanks for sharing however i find that the Av and Tv function are about the same ....as i am a normal user only...